Materials for electronic devices

ABSTRACT

The present application concerns compounds for use in electronic devices, processes for preparing the compounds, and electronic devices comprising the compounds.

The present application relates to a fluorene amine compound which issuitable for use in electronic devices, in particular organicelectroluminescent devices (OLEDs).

Electronic devices in the context of this application are understood tomean what are called organic electronic devices, which contain organicsemiconductor materials as functional materials. More particularly,these are understood to mean OLEDs.

The construction of OLEDs in which organic compounds are used asfunctional materials is common knowledge in the prior art. In general,the term OLEDs is understood to mean electronic devices which have oneor more layers comprising organic compounds and emit light onapplication of electrical voltage.

In electronic devices, especially OLEDs, there is great interest inimproving the performance data, especially lifetime, efficiency andoperating voltage. In these aspects, it has not yet been possible tofind any entirely satisfactory solution.

A great influence on the performance data of electronic devices ispossessed by layers having a hole-transporting function, for examplehole-injecting layers, hole transport layers, electron blocking layersand also emitting layers. For use in these layers, there is a continuoussearch for new materials having hole-transporting properties.

In the course of the present invention, it has been found that fluoreneamine compounds which have a dibenzofuran group or similar group bondedvia a spacer group to the bridgehead position of the fluorene, are verywell suited for use as materials with hole transporting function, inparticular for use as materials of the hole transport layer, theelectron blocking layer and/or the emitting layer, more particularly foruse in the hole transport layer and/or the electron blocking layer. Anelectron blocking layer is understood in this context to be a layerwhich is directly adjacent to the emitting layer on the anode side, andwhich serves to block electrons which are present in the emitting layerfrom entering the hole transport layers of the OLED.

When used in electronic devices, in particular in OLEDs, they lead toexcellent results in terms of lifetime, operating voltage and quantumefficiency of the devices. The compounds are also characterized by verygood hole-conducting properties, very good electron-blocking properties,high glass transition temperature, high oxidation stability, goodsolubility, high thermal stability, and low sublimation temperature.

The present application therefore relates to a compound of a formula (I)

where the following applies to the variable groups:

Z is C, if a group —[Ar²]_(n)-A is bonded to it; and Z is selected,identically or differently at each occurrence, from CR¹ and N, if nogroup —[Ar²]_(n)-A is bonded to it;

Y is C, if a group Ar¹ is bonded to it; and Y is selected, identicallyor differently on each occurrence, from CR³ and N, if no group Ar¹ isbonded to it;

X is O or S;

Ar¹ is, identically or differently at each occurrence, selected fromaromatic ring systems having 6 to 40 aromatic ring atoms, which aresubstituted by radicals R⁴, and heteroaromatic ring systems having 5 to40 aromatic ring atoms, which are substituted by radicals R⁴;

Ar² is, identically or differently at each occurrence, selected fromaromatic ring systems having 6 to 40 aromatic ring atoms, which aresubstituted by radicals R⁵, and heteroaromatic ring systems having 5 to40 aromatic ring atoms, which are substituted by radicals R⁵;

A corresponds to the following formula

which is bonded via the dotted line;

Ar³ and Ar⁴ are, identically or differently at each occurrence, selectedfrom aromatic ring systems having 6 to 40 aromatic ring atoms, which aresubstituted by radicals R⁵, and heteroaromatic ring systems having 5 to40 aromatic ring atoms, which are substituted by radicals R⁵;

T is a single bond or a divalent group selected from C(R⁵)₂, Si(R⁵)₂,N(R⁵), O, and S;

k is 0 or 1, where k=0 means that T does not occur and the groups Ar³and Ar⁴ are not connected;

R¹ is selected, identically or differently at each occurrence, from H,D, F, Cl, Br, I, C(═O)R⁶, CN, Si(R⁶)₃, N(R⁶)₂, P(═O)(R⁶)₂, OR⁶, S(═O)R⁶,S(═O)₂R⁶, straight-chain alkyl or alkoxy groups having 1 to 20 C atoms,branched or cyclic alkyl or alkoxy groups having 3 to 20 C atoms,alkenyl or alkynyl groups having 2 to 20 C atoms, aromatic ring systemshaving 6 to 40 aromatic ring atoms, and heteroaromatic ring systemshaving 5 to 40 aromatic ring atoms; where two or more radicals R¹ may beconnected to each other to form a ring; where the said alkyl, alkoxy,alkenyl and alkynyl groups and the said aromatic and heteroaromatic ringsystems are in each case substituted by radicals R⁶, and where one ormore CH₂ groups in the said alkyl, alkoxy, alkenyl and alkynyl groupsmay in each case be replaced by —R⁶C═CR⁶—, —C≡C—, Si(R⁶)₂, C═O, C═NR⁶,—C(═O)O—, —C(═O)NR⁶—, NR⁶, P(═O)(R⁶), —O—, —S—, SO or SO₂;

R² is selected, identically or differently at each occurrence, from H,D, F, Cl, Br, I, CN, Si(R⁶)₃, N(R⁶)₂, straight-chain alkyl or alkoxygroups having 1 to 20 C atoms, branched or cyclic alkyl or alkoxy groupshaving 3 to 20 C atoms, alkenyl or alkynyl groups having 2 to 20 Catoms, aromatic ring systems having 6 to 40 aromatic ring atoms, andheteroaromatic ring systems having 5 to 40 aromatic ring atoms; wherethe said alkyl, alkoxy, alkenyl and alkynyl groups and the said aromaticand heteroaromatic ring systems are in each case substituted by radicalsR⁶, and where one or more CH₂ groups in the said alkyl, alkoxy, alkenyland alkynyl groups may in each case be replaced by —R⁶C═CR⁶—, —C≡C—,Si(R⁶)₂, C═O, C═NR⁶, —C(═O)O—, —C(═O)NR⁶—, NR⁶, P(═O)(R⁶), —O—, —S—, SOor SO₂;

R³ is selected, identically or differently at each occurrence, from H,D, F, Cl, Br, I, C(═O)R⁶, CN, Si(R⁶)₃, N(R⁶)₂, P(═O)(R⁶)₂, OR⁶, S(═O)R⁶,S(═O)₂R⁶, straight-chain alkyl or alkoxy groups having 1 to 20 C atoms,branched or cyclic alkyl or alkoxy groups having 3 to 20 C atoms,alkenyl or alkynyl groups having 2 to 20 C atoms, aromatic ring systemshaving 6 to 40 aromatic ring atoms, and heteroaromatic ring systemshaving 5 to 40 aromatic ring atoms; where two or more radicals R³ may beconnected to each other to form a ring; where the said alkyl, alkoxy,alkenyl and alkynyl groups and the said aromatic and heteroaromatic ringsystems are in each case substituted by radicals R⁶, and where one ormore CH₂ groups in the said alkyl, alkoxy, alkenyl and alkynyl groupsmay in each case be replaced by —R⁶C═CR⁶—, —C≡C—, Si(R⁶)₂, C═O, C═NR⁶,—C(═O)O—, —C(═O)NR⁶—, NR⁶, P(═O)(R⁶), —O—, —S—, SO or SO₂;

R⁴ is selected, identically or differently at each occurrence, from H,D, F, Cl, Br, I, C(═O)R⁶, CN, Si(R⁶)₃, N(R⁶)₂, P(═O)(R⁶)₂, OR⁶, S(═O)R⁶,S(═O)₂R⁶, straight-chain alkyl or alkoxy groups having 1 to 20 C atoms,branched or cyclic alkyl or alkoxy groups having 3 to 20 C atoms,alkenyl or alkynyl groups having 2 to 20 C atoms, aromatic ring systemshaving 6 to 40 aromatic ring atoms, and heteroaromatic ring systemshaving 5 to 40 aromatic ring atoms; where two or more radicals R⁴ may beconnected to each other to form a ring; where the said alkyl, alkoxy,alkenyl and alkynyl groups and the said aromatic and heteroaromatic ringsystems are in each case substituted by radicals R⁶, and where one ormore CH₂ groups in the said alkyl, alkoxy, alkenyl and alkynyl groupsmay in each case be replaced by —R⁶C═CR⁶—, —C≡C—, Si(R⁶)₂, C═O, C═NR⁶,—C(═O)O—, —C(═O)NR⁶—, NR⁶, P(═O)(R⁶), —O—, —S—, SO or SO₂;

R⁵ is selected, identically or differently at each occurrence, from H,D, F, Cl, Br, I, C(═O)R⁶, CN, Si(R⁶)₃, N(R⁶)₂, P(═O)(R⁶)₂, OR⁶, S(═O)R⁶,S(═O)₂R⁶, straight-chain alkyl or alkoxy groups having 1 to 20 C atoms,branched or cyclic alkyl or alkoxy groups having 3 to 20 C atoms,alkenyl or alkynyl groups having 2 to 20 C atoms, aromatic ring systemshaving 6 to 40 aromatic ring atoms, and heteroaromatic ring systemshaving 5 to 40 aromatic ring atoms; where two or more radicals R⁵ may beconnected to each other to form a ring; where the said alkyl, alkoxy,alkenyl and alkynyl groups and the said aromatic and heteroaromatic ringsystems are in each case substituted by radicals R⁶, and where one ormore CH₂ groups in the said alkyl, alkoxy, alkenyl and alkynyl groupsmay in each case be replaced by —R⁶C═CR⁶—, —C≡C—, Si(R⁶)₂, C═O, C═NR⁶,—C(═O)O—, —C(═O)NR⁶—, NR⁶, P(═O)(R⁶), —O—, —S—, SO or SO₂;

R⁶ is selected, identically or differently at each occurrence, from H,D, F, Cl, Br, I, C(═O)R⁷, CN, Si(R⁷)₃, N(R⁷)₂, P(═O)(R⁷)₂, OR⁷, S(═O)R⁷,S(═O)₂R⁷, straight-chain alkyl or alkoxy groups having 1 to 20 C atoms,branched or cyclic alkyl or alkoxy groups having 3 to 20 C atoms,alkenyl or alkynyl groups having 2 to 20 C atoms, aromatic ring systemshaving 6 to 40 aromatic ring atoms, and heteroaromatic ring systemshaving 5 to 40 aromatic ring atoms; where two or more radicals R⁶ may beconnected to each other to form a ring; where the said alkyl, alkoxy,alkenyl and alkynyl groups and the said aromatic and heteroaromatic ringsystems are in each case be substituted by radicals R⁷, and where one ormore CH₂ groups in the said alkyl, alkoxy, alkenyl and alkynyl groupsmay in each case be replaced by —R⁷C═CR⁷—, —C≡C—, Si(R⁷)₂, C═O, C═NR⁷,—C(═O)O—, —C(═O)NR⁷—, NR⁷, P(═O)(R⁷), —O—, —S—, SO or SO₂;

R⁷ is selected, identically or differently at each occurrence, from H,D, F, Cl, Br, I, CN, alkyl groups having 1 to 20 C atoms, aromatic ringsystems having 6 to 40 C atoms, or heteroaromatic ring systems having 5to 40 aromatic ring atoms; where the said alkyl groups, aromatic ringsystems and heteroaromatic ring systems may be substituted by one ormore radicals selected from F and CN;

m is 1, 2, 3, or 4;

n is 0, 1, 2, 3, or 4.

The following definitions apply to the chemical groups used as generaldefinitions. They apply insofar as no more specific definitions aregiven.

An aryl group here is taken to mean either a single aromatic ring, forexample benzene, or a condensed aromatic polycycle, for examplenaphthalene, phenanthrene, or anthracene. A condensed aromatic polycyclein the sense of the present application consists of two or more singlearomatic rings which are condensed with one another. An aryl group inthe sense of this invention contains 6 to 40 aromatic ring atoms, ofwhich none is a heteroatom.

A heteroaryl group here is taken to mean either a single heteroaromaticring, such as pyridine, pyrimidine or thiophene, or a condensedheteroaromatic polycycle, such as quinoline or carbazole. A condensedheteroaromatic polycycle in the sense of the present applicationconsists of two or more single aromatic or heteroaromatic rings, whichare condensed with one another, where at least one of the two or moresingle aromatic or heteroaromatic rings is a heteroaromatic ring. Aheteroaryl group in the sense of this invention contains 5 to 40aromatic ring atoms, at least one of which is a heteroatom. Theheteroatoms are preferably selected from N, O and S.

An aryl or heteroaryl group, which may in each case be substituted bythe above-mentioned radicals, is taken to mean, in particular, a groupderived from benzene, naphthalene, anthracene, phenanthrene, pyrene,dihydropyrene, chrysene, perylene, fluoranthene, benzanthracene,benzophenanthrene, tetracene, pentacene, benzopyrene, furan, benzofuran,isobenzofuran, dibenzofuran, thiophene, benzothiophene,isobenzothiophene, dibenzothiophene, pyrrole, indole, isoindole,carbazole, pyridine, quinoline, isoquinoline, acridine, phenanthridine,benzo-5,6-quinoline, benzo-6,7-quinoline, benzo-7,8-quinoline,phenothiazine, phenoxazine, pyrazole, indazole, imidazole,benzimidazole, benzimidazolo[1,2-a]benzimidazole, naphthimidazole,phenanthrimidazole, pyridimidazole, pyrazinimidazole,quinoxalinimidazole, oxazole, benzoxazole, naphthoxazole, anthroxazole,phenanthroxazole, isoxazole, 1,2-thiazole, 1,3-thiazole, benzothiazole,pyridazine, benzopyridazine, pyrimidine, benzopyrimidine, quinoxaline,pyrazine, phenazine, naphthyridine, azacarbazole, benzocarboline,phenanthroline, 1,2,3-triazole, 1,2,4-triazole, benzotriazole,1,2,3-oxadiazole, 1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,3,4-oxadiazole,1,2,3-thiadiazole, 1,2,4-thiadiazole, 1,2,5-thiadiazole,1,3,4-thiadiazole, 1,3,5-triazine, 1,2,4-triazine, 1,2,3-triazine,tetrazole, 1,2,4,5-tetrazine, 1,2,3,4-tetrazine, 1,2,3,5-tetrazine,purine, pteridine, indolizine and benzothiadiazole.

An aromatic ring system in the sense of this invention is a system whichdoes not necessarily contain only aryl groups, but which mayadditionally contain one or more non-aromatic rings, which are condensedwith at least one aryl group. Such non-aromatic rings containexclusively carbon atoms as ring atoms. Examples of groups embraced bysuch definition are tetrahydronaphthalene, fluorene, andspirobifluorene. Furthermore, the term aromatic ring system isunderstood to embrace systems consisting of two or more aromatic ringsystems which are connected to each other via single bonds, such asbiphenyl, terphenyl, 7-phenyl-2-fluorenyl and quaterphenyl. An aromaticring system in the sense of this invention contains 6 to 40 C atoms andno heteroatoms as ring atoms of the ring system. An aromatic ring systemin the sense of this application does not comprise any heteroarylgroups, as defined above.

A heteroaromatic ring system is defined in analogy to the aromatic ringsystem above, but with the difference that it must obtain at least oneheteroatom as one of the ring atoms. As it is the case for the aromaticring system, it does not necessarily contain only aryl and heteroarylgroups, but it may additionally contain one or more non-aromatic rings,which are condensed with at least one aryl or heteroaryl group. Thenon-aromatic rings may contain only carbon atoms as ring atoms, or theymay contain additionally one or more heteroatoms, where the heteroatomsare preferably selected from N, O and S. An example for such aheteroaromatic ring system is benzpyranyl. Furthermore, the termheteroaromatic ring system is understood to embrace systems consistingof two or more aromatic or heteroaromatic ring systems, which areconnected to each other via single bonds, such as4,6-diphenyl-2-triazinyl. A heteroaromatic ring system in the sense ofthis invention contains 5 to 40 ring atoms, which are selected fromcarbon and heteroatoms, where at least one of the ring atoms is aheteroatom. The heteroatoms are preferably selected from N, O or S.

The terms “heteroaromatic ring system” and “aromatic ring system”according to the definition of the present application differ from eachother by the fact that the aromatic ring system cannot comprise anyheteroatom as ring atom, whereas the heteroaromatic ring system mustcomprise at least one heteroatom as ring atom. Such heteroatom may bepresent as a ring atom of a non-aromatic heterocyclic ring of thesystem, or as a ring atom of an aromatic heterocyclic ring of thesystem.

According to the above, any aryl group, as defined above, is embraced bythe term “aromatic ring system”, as defined above, and any heteroarylgroup, as defined above, is embraced by the term “heteroaromatic ringsystem”, as defined above.

An aromatic ring system having 6 to 40 aromatic ring atoms or aheteroaromatic ring system having 5 to 40 aromatic ring atoms is inparticular a group which is derived from the above mentioned aryl orheteroaryl groups, or from biphenyl, terphenyl, quaterphenyl, fluorene,spirobifluorene, dihydrophenanthrene, dihydropyrene, tetrahydropyrene,indenofluorene, truxene, isotruxene, spirotruxene, spiroisotruxene, andindenocarbazole, or from any combinations of these groups.

For the purposes of the present invention, a straight-chain alkyl grouphaving 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to20 C atoms or an alkenyl or alkynyl group having 2 to 20 C atoms, inwhich, in addition, individual H atoms or CH₂ groups may be substitutedby the groups mentioned above under the definition of the radicals, ispreferably taken to mean the radicals methyl, ethyl, n-propyl, i-propyl,n-butyl, i-butyl, s-butyl, t-butyl, 2-methylbutyl, n-pentyl, s-pentyl,cyclopentyl, neopentyl, n-hexyl, cyclohexyl, neohexyl, n-heptyl,cycloheptyl, n-octyl, cyclooctyl, 2-ethylhexyl, trifluoromethyl,pentafluoroethyl, 2,2,2-trifluoroethyl, ethenyl, propenyl, butenyl,pentenyl, cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl,octenyl, cyclooctenyl, ethynyl, propynyl, butynyl, pentynyl, hexynyl oroctynyl.

An alkoxy or thioalkyl group having 1 to 20 C atoms is preferably takento mean methoxy, trifluoromethoxy, ethoxy, n-propoxy, i-propoxy,n-butoxy, i-butoxy, s-butoxy, t-butoxy, n-pentoxy, s-pentoxy,2-methylbutoxy, n-hexoxy, cyclohexyloxy, n-heptoxy, cycloheptyloxy,n-octyloxy, cyclooctyl-oxy, 2-ethylhexyloxy, pentafluoroethoxy,2,2,2-trifluoroethoxy, methylthio, ethylthio, n-propylthio,i-propylthio, n-butylthio, i-butylthio, s-butylthio, t-butylthio,n-pentylthio, s-pentylthio, n-hexylthio, cyclohexylthio, n-heptyl-thio,cycloheptylthio, n-octylthio, cyclooctylthio, 2-ethylhexylthio,trifluoro-methylthio, pentafluoroethylthio, 2,2,2-trifluoroethylthio,ethenylthio, propenylthio, butenylthio, pentenylthio, cyclopentenylthio,hexenylthio, cyclohexenylthio, heptenylthio, cycloheptenylthio,octenylthio, cyclooctenyl-thio, ethynylthio, propynylthio, butynylthio,pentynylthio, hexynylthio, heptynylthio or octynylthio.

The phrase “two or more radicals may be connected to each other to forma ring” shall be understood to include the case that the two radicalsare connected by a chemical bond. Additionally, the phrase shall beunderstood to include the case that one of the two radicals is H, thisradical H is removed, and the other of the two radicals forms a ring bybeing connected to the position, to which this radical H was initiallybonded. Additionally, this phrase shall be understood to include thecase that both of the two radicals are H, they are both removed, and thepositions to which the two radicals H were bonded are connected by asingle bond to form a ring.

For the purposes of the present application, if a group is depicted asbonded to a ring having multiple bonding positions, and the group has anindex which is an integer, this means that the respective group ispresent multiple times on the ring. E.g. if a group —[R¹]₄ is shown in aformula, bonded to an aromatic ring of the fluorene moiety of theformula, this means that all four positions on that aromatic ring aresubstituted with R¹.

The compound according to formula (I) is preferably a monoamine. Amonoamine is understood to be a compound which has only one triarylaminegroup, preferably a compound which has only one amine group.

The group —[Ar²]_(n)-A can be bonded in any of positions 1, 2, 3 and 4on the fluorene sub-structure of formula (I). Preferably, it is bondedin position 2 or 4, more preferably, in position 2.

The positions on the fluorene sub-structure of formula (I) are numberedas follows:

The group

of formula (I) is preferably bonded in the following position to therest of the formula (I):

where the dotted bond is the bond which connects the group to the restof the formula.

According to a preferred embodiment, Z is C, if a group —[Ar²]_(n)-A isbonded to it; and Z is CR¹, if no group —[Ar²]_(n)-A is bonded to it.

According to a preferred embodiment, Y is C, if a group Ar¹ is bonded toit; and Z is CR¹, if no group Ar¹ is bonded to it.

According to a preferred embodiment, X is O.

According to a preferred embodiment, Ar¹ is selected from divalentgroups derived from phenyl, biphenyl, terphenyl, naphthalene, fluorene,indenofluorene, indenocarbazole, spirobifluorene, dibenzofuran,dibenzothiophene, and carbazole, which are optionally substituted withone or more radicals R⁴, more preferably selected from divalent groupsderived from phenyl, biphenyl and fluorene, which are optionallysubstituted with one or more radicals R⁴, most preferably selected from1,2-phenylene, 1,3-phenylene and 1,4-phenylene, of which 1,4-phenyleneis preferred, where the phenylene groups are optionally substituted withone or more radicals R⁴ and are preferably unsubstituted.

Index m is preferably 1 or 2, most preferably 1.

Preferred groups —[Ar¹]_(m)— for the case of m=1 are selected fromdivalent groups derived from phenyl, biphenyl, terphenyl, naphthalene,fluorene, indenofluorene, indenocarbazole, spirobifluorene,dibenzofuran, dibenzothiophene, and carbazole, which are substitutedwith radicals R⁴, more preferably selected from divalent groups derivedfrom phenyl, biphenyl and fluorene, which are substituted with radicalsR⁴, most preferably selected from 1,2-phenylene, 1,3-phenylene and1,4-phenylene, of which 1,4-phenylene is preferred, where the phenylenegroups are substituted with radicals R⁴, where in such case, radicals R⁴are preferably H.

Preferred groups Ar² are selected from divalent groups derived fromphenyl, biphenyl, terphenyl, naphthalene, fluorene, indenofluorene,indenocarbazole, spirobifluorene, dibenzofuran, dibenzothiophene, andcarbazole, which are substituted with radicals R⁵, more preferablyselected from divalent groups derived from phenyl, biphenyl andfluorene, which are substituted with radicals R⁵.

According to a preferred embodiment, index n is 0, so that the group Ar²is not present, and the fluorene moiety and the amine nitrogen informula (I) are directly connected to each other.

According to an alternative preferred embodiment, index n is 1 or 2,preferably 1.

Preferred groups —[Ar^(2]) _(n)— for the case that n=1 are selected fromdivalent groups derived from phenyl, biphenyl, terphenyl, naphthalene,fluorene, indenofluorene, indenocarbazole, spirobifluorene,dibenzofuran, dibenzothiophene, and carbazole, which are substitutedwith radicals R⁵, more preferably selected from divalent groups derivedfrom phenyl, naphthyl, biphenyl and fluorene, which are substituted withradicals R⁵.

Particularly preferred groups —[Ar²]_(n)— for the case that n=1 areselected from the following groups

where the dotted bonds are the bonds to the rest of the formula (I), andthe groups are substituted with radicals R⁵ at all free positions.

Among the above-mentioned groups, groups according to formulae (Ar²-1),(Ar²-2), (Ar²-3), (Ar²-4), (Ar²-15), (Ar²-20), (Ar²-25) and (Ar²-36) areparticularly preferred.

According to one preferred embodiment of the invention, the groups Ar³and Ar⁴ in group A are not linked to each other by a group T, i.e. k is0.

According to another preferred embodiment, the groups Ar³ and Ar⁴ arelinked to each other by a group T, i.e. k is 1. In this case, T ispreferably a single bond. Preferred embodiments of group A for the casek=1 are shown in the following:

where the dotted line is the bond to the rest of formula (I).

According to a preferred embodiment, Ar³ and Ar⁴ are selected,identically or differently, from monovalent groups derived from benzene,biphenyl, terphenyl, quaterphenyl, naphthalene, fluorene, particularly9,9′-dimethylfluorene and 9,9′-diphenylfluorene, 9-sila-fluorene,particularly 9,9′-dimethyl-9-silafluorene and9,9′-diphenyl-9-silafluorene, benzofluorene, spirobifluorene,indenofluorene, indenocarbazole, dibenzofuran, dibenzothiophene,benzocarbazole, carbazole, benzofuran, benzothiophene, indole,quinoline, pyridine, pyrimidine, pyrazine, pyridazine, and triazine,where each of the monovalent groups is substituted with radicals R⁵.According to an alternative preferred embodiment, groups Ar³ and Ar⁴ areselected, identically or differently, from combinations of 2 to 4groups, preferably 2 groups derived from benzene, biphenyl, terphenyl,quaterphenyl, naphthalene, fluorene, particularly 9,9′-dimethylfluoreneand 9,9′-diphenylfluorene, 9-sila-fluorene, particularly9,9′-dimethyl-9-silafluorene and 9,9′-diphenyl-9-silafluorene,benzofluorene, spirobifluorene, indenofluorene, indenocarbazole,dibenzofuran, dibenzothiophene, benzocarbazole, carbazole, benzofuran,benzothiophene, indole, quinoline, pyridine, pyrimidine, pyrazine,pyridazine, and triazine, where each of the groups is substituted withradicals R⁵.

Particularly preferred groups Ar³ and Ar⁴ are selected, identically ordifferently, from phenyl, biphenyl, terphenyl, quaterphenyl, naphthyl,fluorenyl, particularly 9,9′-dimethylfluorenyl and9,9′-diphenylfluorenyl, benzofluorenyl, spirobifluorenyl,indenofluorenyl, indenocarbazolyl, dibenzofuranyl, dibenzothiophenyl,carbazolyl, benzofuranyl, benzothiophenyl, benzo-condenseddibenzofuranyl, benzo-condensed dibenzothiophenyl, phenyl substitutedwith naphthyl, phenyl substituted with fluorenyl, phenyl substitutedwith spirobifluorenyl, phenyl substituted with dibenzofuranyl, phenylsubstituted with dibenzothiophene, phenyl substituted with carbazolyl,phenyl substituted with pyridyl, phenyl substituted with pyrimidyl, andphenyl substituted with triazinyl, where the groups are each substitutedwith radicals R⁵.

Preferred embodiments of groups Ar³ and Ar⁴ are shown in the following:

where the dotted lines are the bonds to the nitrogen atom of the groupA.

Particularly preferred among the above formulae are formulae Ar-1, Ar-2,Ar-4, Ar-5, Ar-50, Ar-74, Ar-78, Ar-82, Ar-107, Ar-108, Ar-117, Ar-134,Ar-139, Ar-150, and Ar-172.

Preferably, R¹ is selected, identically or differently, from H, D, F,CN, Si(R⁶)₃, N(R⁶)₂, straight-chain alkyl or alkoxy groups having 1 to20 C atoms, branched or cyclic alkyl or alkoxy groups having 3 to 20 Catoms, aromatic ring systems having 6 to 40 aromatic ring atoms, andheteroaromatic ring systems having 5 to 40 aromatic ring atoms; wherethe said alkyl and alkoxy groups and the said aromatic andheteroaromatic ring systems are substituted by radicals R⁶, and whereone or more CH₂ groups in the said alkyl and alkoxy groups may in eachcase be replaced by —C≡C—, —R⁶C═CR⁶—, Si(R⁶)₂, C═O, C═NR⁶, —NR⁶—, —O—,—S—, —C(═O)O— or —C(═O)NR⁶—. Preferably, R¹ is not N(R⁶)₂. Particularlypreferably, R¹ does not comprise any amine group. More preferably, R¹ isselected, identically or differently, from H, D, F, CN, Si(R⁶)₃,straight-chain alkyl groups having 1 to 20 C atoms, which are optionallydeuterated and/or fluorinated, branched or cyclic alkyl groups having 3to 20 C atoms, which are optionally deuterated and/or fluorinated,aromatic ring systems having 6 to 40 aromatic ring atoms, andheteroaromatic ring systems having 5 to 40 aromatic ring atoms; wherethe said alkyl groups and the said aromatic and heteroaromatic ringsystems are substituted by radicals R⁶. Most preferably, R¹ is H.

Preferred embodiments of R¹ are selected from the following groups:

where the dotted bond is the bond to the rest of formula (I).

Preferably, R² is F, Si(R⁶)₃, a straight-chain alkyl group having 1 to20 C atoms, a branched or cyclic alkyl group having 3 to 20 C atoms, anaromatic ring system having 6 to 40 aromatic ring atoms, or aheteroaromatic ring system having 5 to 40 aromatic ring atoms; where thesaid alkyl group and the said aromatic or heteroaromatic ring system aresubstituted by radicals R⁶. More preferably, R² is an aromatic ringsystem having 6 to 40 aromatic ring atoms, which is substituted byradicals R⁶. Most preferably, R² is phenyl, biphenyl, terphenyl, phenylsubstituted with dibenzofuran, or phenyl substituted withdibenzothiophene, where each of the groups is substituted with radicalsR⁶, which are in this case preferably H. The strongest preference isthat R² is phenyl, which is substituted with radicals R⁶, which are inthis case preferably H.

Furthermore, preferably, R² is selected from the following groups

where the dotted bond represents the bond to the rest of the formula.

Preferably, R³ is selected, identically or differently, from H, D, F,CN, Si(R⁶)₃, N(R⁶)₂, straight-chain alkyl or alkoxy groups having 1 to20 C atoms, branched or cyclic alkyl or alkoxy groups having 3 to 20 Catoms, aromatic ring systems having 6 to 40 aromatic ring atoms, andheteroaromatic ring systems having 5 to 40 aromatic ring atoms; wherethe said alkyl and alkoxy groups and the said aromatic andheteroaromatic ring systems are substituted by radicals R⁶, and whereone or more CH₂ groups in the said alkyl and alkoxy groups may in eachcase be replaced by —C≡C—, —R⁶C═CR⁶—, Si(R⁶)₂, C═O, C═NR⁶, —NR⁶—, —O—,—S—, —C(═O)O— or —C(═O)NR⁶—. More preferably, R³ is selected,identically or differently, from H, D, F, CN, Si(R⁶)₃, straight-chainalkyl groups having 1 to 20 C atoms, branched or cyclic alkyl groupshaving 3 to 20 C atoms, aromatic ring systems having 6 to 40 aromaticring atoms, and heteroaromatic ring systems having 5 to 40 aromatic ringatoms; where the said alkyl groups and the said aromatic andheteroaromatic ring systems are substituted by radicals R⁶. Mostpreferably, R³ is H.

Preferably, R⁴ is selected, identically or differently, from H, D, F,CN, Si(R⁶)₃, N(R⁶)₂, straight-chain alkyl or alkoxy groups having 1 to20 C atoms, branched or cyclic alkyl or alkoxy groups having 3 to 20 Catoms, aromatic ring systems having 6 to 40 aromatic ring atoms, andheteroaromatic ring systems having 5 to 40 aromatic ring atoms; wherethe said alkyl and alkoxy groups and the said aromatic andheteroaromatic ring systems are substituted by radicals R⁶, and whereone or more CH₂ groups in the said alkyl and alkoxy groups may in eachcase be replaced by —C≡C—, —R⁶C═CR⁶—, Si(R⁶)₂, C═O, C═NR⁶, —NR⁶—, —O—,—S—, —C(═O)O— or —C(═O)NR⁶—. More preferably, R⁴ is selected,identically or differently, from H, D, F, CN, Si(R⁶)₃, straight-chainalkyl groups having 1 to 20 C atoms, branched or cyclic alkyl groupshaving 3 to 20 C atoms, aromatic ring systems having 6 to 40 aromaticring atoms, and heteroaromatic ring systems having 5 to 40 aromatic ringatoms; where the said alkyl groups and the said aromatic andheteroaromatic ring systems are substituted by radicals R⁶. Mostpreferably, R⁴ is selected, identically or differently, from H, alkylgroups having 1 to 10 C atoms, preferably methyl, iso-propyl andtert-butyl, and aromatic ring systems having 6 to 40 aromatic ringatoms, which are substituted with groups R⁶, preferably phenyl.

Preferably, R⁵ is selected, identically or differently, from H, D, F,CN, Si(R⁶)₃, N(R⁶)₂, straight-chain alkyl or alkoxy groups having 1 to20 C atoms, branched or cyclic alkyl or alkoxy groups having 3 to 20 Catoms, aromatic ring systems having 6 to 40 aromatic ring atoms, andheteroaromatic ring systems having 5 to 40 aromatic ring atoms; wherethe said alkyl and alkoxy groups and the said aromatic andheteroaromatic ring systems are substituted by radicals R⁶, and whereone or more CH₂ groups in the said alkyl and alkoxy groups may in eachcase be replaced by —C≡C—, —R⁶C═CR⁶—, Si(R⁶)₂, C═O, C═NR⁶, —NR⁶—, —O—,—S—, —C(═O)O— or —C(═O)NR⁶—. More preferably, R⁵ is selected,identically or differently, from H, D, F, CN, Si(R⁶)₃, straight-chainalkyl groups having 1 to 20 C atoms, branched or cyclic alkyl groupshaving 3 to 20 C atoms, aromatic ring systems having 6 to 40 aromaticring atoms, and heteroaromatic ring systems having 5 to 40 aromatic ringatoms; where the said alkyl groups and the said aromatic andheteroaromatic ring systems are substituted by radicals R⁶. Mostpreferably, R⁵ is selected, identically or differently, from H, alkylgroups having 1 to 10 C atoms, preferably methyl, iso-propyl andtert-butyl, and aromatic ring systems having 6 to 40 aromatic ringatoms, which are substituted with groups R⁶, preferably phenyl.

Preferably, R⁶ is selected, identically or differently, from H, D, F,CN, Si(R⁷)₃, N(R⁷)₂, straight-chain alkyl or alkoxy groups having 1 to20 C atoms, branched or cyclic alkyl or alkoxy groups having 3 to 20 Catoms, aromatic ring systems having 6 to 40 aromatic ring atoms, andheteroaromatic ring systems having 5 to 40 aromatic ring atoms; wherethe said alkyl and alkoxy groups and the said aromatic andheteroaromatic ring systems are substituted by radicals R⁷, and whereone or more CH₂ groups in the said alkyl and alkoxy groups may in eachcase be replaced by —C≡C—, —R⁷C═CR⁷—, Si(R⁷)₂, C═O, C═NR⁷, —NR′—, —O—,—S—, —C(═O)O— or —C(═O)NR⁷—. More preferably, R⁶ is selected,identically or differently, from H, D, F, CN, Si(R⁷)₃, straight-chainalkyl groups having 1 to 20 C atoms, branched or cyclic alkyl groupshaving 3 to 20 C atoms, aromatic ring systems having 6 to 40 aromaticring atoms, and heteroaromatic ring systems having 5 to 40 aromatic ringatoms; where the said alkyl groups and the said aromatic andheteroaromatic ring systems are substituted by radicals R⁷.

Preferably, R⁷ is H.

Preferred embodiments according to formula (I) conform to the followingformulae (I-A) to (I-H)

where the variable groups and indices are defined as above, andpreferably conform to their preferred embodiments mentioned above.

Particularly preferably, in the above formulae, moiety —[Ar¹]_(m)— isphenylene, preferably p-phenylene, or biphenylene, preferablypara-biphenylene, each of which is substituted with radicals R⁴, whichare preferably H. Most preferably, —[Ar¹]_(m)— is phenylene, preferablyp-phenylene, each of which is substituted by radicals R⁴, which arepreferably H.

Among the above formulae, formulae (I-A) to (I-D) are preferred,particularly formulae (I-B) and (I-D), most preferred is formula (I-B).

In the case of formulae (I-E) to (I-H), it is preferred that Ar³ and Ar⁴are selected, identically or differently, from phenyl, fluorenyl,carbazolyl, dibenzofuranyl and dibenzothiophenyl, each of which issubstituted with radicals R⁵. Furthermore, it is preferred that thegroups Ar³ and Ar⁴ are connected by the single bond in a position whichis ortho to their bond to the amine nitrogen, so that a five-ringcontaining the nitrogen atom is formed. Particularly preferably, the twoembodiments occur in combination, so that carbazole, indenocarbazole,indolocarbazole, benzofuran-condensed carbazole orbenzothiophene-condensed carbazole are formed by the group

Preferably, R² conforms to the above-mentioned formulae (R²-1) to(R²-4).

Furthermore, preferred embodiments of formula (I) conform to one of thefollowing formulae

where X is selected, identically or differently, from O and S, and X ispreferably O, and where the further variable groups and indices aredefined as above, and preferably conform to their preferred embodiments.It is preferred that Ar² is selected from divalent groups derived fromphenyl, biphenyl, terphenyl, naphthalene, fluorene, indenofluorene,indenocarbazole, spirobifluorene, dibenzofuran, dibenzothiophene, andcarbazole, which are substituted with radicals R⁵, more preferablyselected from divalent groups derived from phenyl, naphthyl, biphenyland fluorene, which are substituted with radicals R⁵. Furthermore, it ispreferred that the group Ar² or the amine nitrogen bond to the position2 or 4, preferably 2 of the fluorene moiety. Preferably, R² conforms tothe above-mentioned formulae (R²-1) to (R²-4).

Particularly preferred embodiments of formula (I) conform to thefollowing formulae

where the variable groups and indices are defined as above, andpreferably conform to their preferred embodiments mentioned above. X is,identically or differently, O or S. Particularly preferably, index n is0, or index n is 1. For the case of index n being 1, it is preferredthat —[Ar²]_(n)— is selected from divalent groups derived from phenyl,biphenyl, terphenyl, naphthalene, fluorene, indenofluorene,indenocarbazole, spirobifluorene, dibenzofuran, dibenzothiophene, andcarbazole, which are substituted with radicals R⁵, more preferablyselected from divalent groups derived from phenyl, naphthyl, biphenyland fluorene, which are substituted with radicals R⁵. Furthermore, it ispreferred that X is O.

Preferred embodiments of compounds according to formula (I) are shownbelow:

The compounds according to formula (I) are synthetically accessible forthe person skilled in the art, based on the following information.

A preferred synthetic method for preparing a compound according toformula (I) is shown in Scheme 1 below. Although not shown in the schemefor reasons of simplification, the structures may be substituted withorganic radicals.

V¹=Halogen, preferably Br or I

V²=reactive group, preferably CI or Br

V³=reactive group, preferably boronic acid or boronic ester

Ar=aromatic group

HetAr=optionally substituted dibenzofuran or dibenzothiophene

R=organic radical, preferably alkyl or aromatic ring system

T=single bond or organic linking group, preferably, O, S, CR₂ or SiR₂

k=0 or 1, where for k=0, the groups Ar are not linked to each other

In a first step, a biphenyl compound which is substituted with areactive group V¹ in the position ortho to the connecting bond betweenthe two phenyl groups, and a further reactive group V², is metalated inthe position of the group V¹. The metalation reaction is preferably alithiation reaction or a Grignard reaction. The metalated intermediateis then reacted with a carbonyl derivative, which has the dibenzofuranor dibenzothiophene group bonded via a spacer. The resulting tertiaryalcohol is cyclized to a fluorene under acidic and/or lewis acidicconditions. The resulting fluorene derivative, which has a reactivegroup V² bonded to it, is then further reacted in a Buchwald reaction,resulting in the corresponding amine or carbazolyl derivative of thefluorene, or it is further reacted in a Suzuki reaction, resulting inthe corresponding amine or carbazolyl derivative of the fluorene, whichhas an aromatic group as a spacer between the amine nitrogen and thefluorene. As an alternative to the Suzuki reaction shown above with agroup V³—Ar—NAr₂, a Suzuki reaction with a group V³—Ar—V⁴ can beperformed, followed by a Buchwald reaction with a group H—NAr₂.

The present application thus relates to a method for preparation of acompound according to formula (I), characterized in that a biphenylderivative which is substituted with two reactive groups, of which atleast one is present in the ortho-position to the phenyl-phenyl bond ofthe biphenyl derivative, is metalated. The metalation reaction ispreferably a lithiation reaction or a Grignard reaction. Then, in asecond step, the metalated biphenyl derivative is added to a carbonylderivative, which has a dibenzofuran or dibenzothiophene group bonded tothe carbonyl group via a spacer. In a third step, the resultingintermediate is cyclized to a fluorene derivative. The cyclizationreaction preferably takes place under acidic and/or Lewis-acidicconditions, most preferably by addition of a strong organic acid, suchas para-toluenesulfonic acid. In a fourth step, the fluorene derivativeis further reacted in a Buchwald reaction, or in a Suzuki reaction.

The above-described first to fourth step are preferably consecutive,meaning that there are no intermediate steps between the first and thesecond, the second and the third, and the third and the fourth step.

The compounds according to the present application, especially compoundssubstituted by reactive leaving groups, such as bromine, iodine,chlorine, boronic acid or boronic ester, may find use as monomers forproduction of corresponding oligomers, dendrimers or polymers. Suitablereactive leaving groups are, for example, bromine, iodine, chlorine,boronic acids, boronic esters, amines, alkenyl or alkynyl groups havinga terminal C—C double bond or C—C triple bond, oxiranes, oxetanes,groups which enter into a cycloaddition, for example a 1,3-dipolarcycloaddition, for example dienes or azides, carboxylic acidderivatives, alcohols and silanes.

The invention therefore further provides oligomers, polymers ordendrimers containing one or more compounds of formula (I), wherein thebond(s) to the polymer, oligomer or dendrimer may be localized at anydesired positions substituted by R¹, R², R³, R⁴, or R⁵ in the formulae.According to the linkage of the compound, the compound is part of a sidechain of the oligomer or polymer or part of the main chain. An oligomerin the context of this invention is understood to mean a compound formedfrom at least three monomer units. A polymer in the context of theinvention is understood to mean a compound formed from at least tenmonomer units. The polymers, oligomers or dendrimers of the inventionmay be conjugated, partly conjugated or nonconjugated. The oligomers orpolymers of the invention may be linear, branched or dendritic. In thestructures having linear linkage, the units of the above formulae may bejoined directly to one another, or they may be joined to one another viaa bivalent group, for example via a substituted or unsubstitutedalkylene group, via a heteroatom or via a bivalent aromatic orheteroaromatic group. In branched and dendritic structures, it ispossible, for example, for three or more units of the above formulae tobe joined via a trivalent or higher-valency group, for example via atrivalent or higher-valency aromatic or heteroaromatic group, to give abranched or dendritic oligomer or polymer.

For the repeat units of the above formulae in oligomers, dendrimers andpolymers, the same preferences apply as described above for thecompounds of the above formulae.

For preparation of the oligomers or polymers, the monomers of theinvention are homopolymerized or copolymerized with further monomers.Suitable and preferred comonomers are chosen from fluorenes,spirobifluorenes, paraphenylenes, carbazoles, thiophenes,dihydrophenanthrenes, cis- and trans-indenofluorenes, ketones,phenanthrenes or else a plurality of these units. The polymers,oligomers and dendrimers typically contain still further units, forexample emitting (fluorescent or phosphorescent) units, for examplevinyltriarylamines or phosphorescent metal complexes, and/or chargetransport units, especially those based on triarylamines.

The polymers and oligomers of the invention are generally prepared bypolymerization of one or more monomer types, of which at least onemonomer leads to repeat units of the above formulae in the polymer.Suitable polymerization reactions are known to those skilled in the artand are described in the literature. Particularly suitable and preferredpolymerization reactions which lead to formation of C—C or C—N bonds arethe Suzuki polymerization, the Yamamoto polymerization, the Stillepolymerization and the Hartwig-Buchwald polymerization.

For the processing of the compounds according to the present applicationfrom a liquid phase, for example by spin-coating or by printing methods,formulations of the compounds according to the present application arerequired. These formulations may, for example, be solutions, dispersionsor emulsions. For this purpose, it may be preferable to use mixtures oftwo or more solvents. Suitable and preferred solvents are, for example,toluene, anisole, o-, m- or p-xylene, methyl benzoate, mesitylene,tetralin, veratrole, THF, methyl-THF, THP, chlorobenzene, dioxane,phenoxytoluene, especially 3-phenoxytoluene, (−)-fenchone,1,2,3,5-tetramethylbenzene, 1,2,4,5-tetramethylbenzene,1-methylnaphthalene, 2-methylbenzothiazole, 2-phenoxyethanol,2-pyrrolidinone, 3-methylanisole, 4-methylanisole, 3,4-dimethylanisole,3,5-dimethylanisole, acetophenone, α-terpineol, benzothiazole, butylbenzoate, cumene, cyclohexanol, cyclohexanone, cyclohexylbenzene,decalin, dodecylbenzene, ethyl benzoate, indane, methyl benzoate, NMP,p-cymene, phenetole, 1,4-diisopropylbenzene, dibenzyl ether, diethyleneglycol butyl methyl ether, triethylene glycol butyl methyl ether,diethylene glycol dibutyl ether, triethylene glycol dimethyl ether,diethylene glycol monobutyl ether, tripropylene glycol dimethyl ether,tetraethylene glycol dimethyl ether, 2-isopropylnaphthalene,pentylbenzene, hexylbenzene, heptylbenzene, octylbenzene,1,1-bis(3,4-dimethylphenyl)ethane or mixtures of these solvents.

The invention therefore further provides a formulation, especially asolution, dispersion or emulsion, comprising at least one compoundaccording to the present application and at least one solvent,preferably an organic solvent. The way in which such solutions can beprepared is known to those skilled in the art and is described, forexample, in WO 2002/072714, WO 2003/019694 and the literature citedtherein.

The compounds according to the present application are suitable for usein electronic devices, especially in organic electroluminescent devices(OLEDs). Depending on the substitution, the compounds are used indifferent functions and layers.

The invention therefore further provides for the use of the compound inan electronic device. This electronic device is preferably selected fromthe group consisting of organic integrated circuits (OICs), organicfield-effect transistors (OFETs), organic thin-film transistors (OTFTs),organic light-emitting transistors (OLETs), organic solar cells (OSCs),organic optical detectors, organic photoreceptors, organic field-quenchdevices (OFQDs), organic light-emitting electrochemical cells (OLECs),organic laser diodes (O-lasers) and more preferably organicelectroluminescent devices (OLEDs).

The invention further provides, as already set out above, an electronicdevice comprising at least one compound according to the presentapplication. This electronic device is preferably selected from theabovementioned devices.

It is more preferably an organic electroluminescent device (OLED)comprising anode, cathode and at least one emitting layer, characterizedin that at least one organic layer, which may be an emitting layer, ahole transport layer or another layer, preferably an emitting layer or ahole transport layer, particularly preferably a hole transport layer,comprises at least one compound according to the present application.

Apart from the cathode, anode and emitting layer, the organicelectroluminescent device may also comprise further layers. These areselected, for example, from in each case one or more hole injectionlayers, hole transport layers, hole blocking layers, electron transportlayers, electron injection layers, electron blocking layers, excitonblocking layers, interlayers, charge generation layers and/or organic orinorganic p/n junctions.

The sequence of the layers of the organic electroluminescent devicecomprising the compound of the above formulae is preferably as follows:anode-hole injection layer-hole transport layer-optionally further holetransport layer(s)-optionally electron blocking layer-emittinglayer-optionally hole blocking layer-electron transport layer-electroninjection layer-cathode. It is additionally possible for further layersto be present in the OLED.

The organic electroluminescent device of the invention may contain twoor more emitting layers. More preferably, these emission layers in thiscase have several emission maxima between 380 nm and 750 nm overall,such that the overall result is white emission; in other words, variousemitting compounds which may fluoresce or phosphoresce and which emitblue, green, yellow, orange or red light are used in the emittinglayers. Especially preferred are three-layer systems, i.e. systemshaving three emitting layers, where the three layers show blue, greenand orange or red emission. The compounds according to the presentapplication are preferably present in the hole transport layer, holeinjection layer, electron blocking layer and emitting layer. In casethey are present in the emitting layer, they are preferably present ashost materials.

It is preferable in accordance with the invention when the compoundaccording to the present application is used in an electronic devicecomprising one or more phosphorescent emitting compounds. In this case,the compound may be present in different layers, preferably in a holetransport layer, an electron blocking layer, a hole injection layer orin an emitting layer.

The term “phosphorescent emitting compounds” typically encompassescompounds where the emission of light is effected through aspin-forbidden transition, for example a transition from an excitedtriplet state or a state having a higher spin quantum number, forexample a quintet state.

Suitable phosphorescent emitting compounds (=triplet emitters) areespecially compounds which, when suitably excited, emit light,preferably in the visible region, and also contain at least one atom ofatomic number greater than 20, preferably greater than 38, and less than84, more preferably greater than 56 and less than 80. Preference isgiven to using, as phosphorescent emitting compounds, compoundscontaining copper, molybdenum, tungsten, rhenium, ruthenium, osmium,rhodium, iridium, palladium, platinum, silver, gold or europium,especially compounds containing iridium, platinum or copper. In thecontext of the present invention, all luminescent iridium, platinum orcopper complexes are considered to be phosphorescent emitting compounds.In general, all phosphorescent complexes as used for phosphorescentOLEDs according to the prior art and as known to those skilled in theart in the field of organic electroluminescent devices are suitable. Itis also possible for the person skilled in the art, without exercisinginventive skill, to use further phosphorescent complexes in combinationwith the compounds according to the present application in organicelectroluminescent devices. Further examples are listed in a table whichfollows.

It is also possible in accordance with the invention to use the compoundaccording to the present application in an electronic device comprisingone or more fluorescent emitting compounds.

In a preferred embodiment of the invention, the compounds according tothe present application are used as hole-transporting material. In thatcase, the compounds are preferably present in a hole transport layer, anelectron blocking layer or a hole injection layer. Particular preferenceis given to use in an electron blocking layer or in a hole transportlayer.

A hole transport layer according to the present application is a layerhaving a hole-transporting function between the anode and emittinglayer.

Hole injection layers and electron blocking layers are understood in thecontext of the present application to be specific embodiments of holetransport layers. A hole injection layer, in the case of a plurality ofhole transport layers between the anode and emitting layer, is a holetransport layer which directly adjoins the anode or is separatedtherefrom only by a single coating of the anode. An electron blockinglayer, in the case of a plurality of hole transport layers between theanode and emitting layer, is that hole transport layer which directlyadjoins the emitting layer on the anode side. Preferably, the OLED ofthe invention comprises two, three or four hole-transporting layersbetween the anode and emitting layer, at least one of which preferablycontains a compound according to the present application, and morepreferably exactly one or two contain a such compound.

If the compound according to the present application is used as holetransport material in a hole transport layer, a hole injection layer oran electron blocking layer, the compound can be used as pure material,i.e. in a proportion of 100%, in the hole transport layer, or it can beused in combination with one or more further compounds. In a preferredembodiment, the organic layer comprising the compound of one of theabove-mentioned formulae then additionally contains one or morep-dopants. p-Dopants used according to the present invention arepreferably those organic electron acceptor compounds capable ofoxidizing one or more of the other compounds in the mixture. Suchp-dopants are preferably present in the hole-injection layer and/or holetransporting layer of the device. The electron-blocking layer preferablydoes not comprise any p-dopants.

Particularly preferred p-dopants are quinodimethane compounds,azaindenofluorenediones, azaphenalenes, azatriphenylenes, 12, metalhalides, preferably transition metal halides, metal oxides, preferablymetal oxides containing at least one transition metal or a metal of maingroup 3, and transition metal complexes, preferably complexes of Cu, Co,Ni, Pd and Pt with ligands containing at least one oxygen atom asbonding site. Preference is further given to transition metal oxides asdopants, preferably oxides of rhenium, molybdenum and tungsten, morepreferably Re₂O₇, MoO₃, WO₃ and ReO₃. Further preferable p-dopants areselected from Bi(III)-containing metal complexes, in particular Bi(III)complexes of benzoic acid or benzoic acid derivatives.

The p-dopants are preferably in substantially homogeneous distributionin the p-doped layers. This can be achieved, for example, bycoevaporation of the p-dopant and the hole transport material matrix.

Preferred p-dopants are especially the following compounds:

In a further preferred embodiment of the invention, the compound is usedas hole transport material in a hole transporting layer, and there is alayer (called hole injection layer) present between anode and this holetransporting layer, which comprises an electron accepting material.Preferably, this electron accepting material is selected from thecompound classes mentioned above for use as p-dopants, particularlypreferably from the compounds (D-1) to (D-14) mentioned above, mostpreferably from the compounds (D-6), (D-7) and (D-14). Preferably, theabove-mentioned hole injection layer comprises one of theabove-mentioned compounds in non-doped form, and with no other compoundsadmixed. Most preferably, it consists of only one of the above-mentionedcompounds and comprises no other compound.

According to a preferred embodiment, a hole transporting or holeinjection layer of the device comprises two or more, preferably two,different hole transporting materials (mixed layer). In such case, thetwo or more different hole transporting materials are preferablyselected from triarylamine compounds, particularly preferred frommono-triarylamine compounds, more particularly preferably from thecompounds listed below as preferred hole-transporting compounds. In casetwo or more different compounds are present in the layer, each of themis preferably present in a proportion of at least 10% by volume,preferably in a proportion of at least 20% by volume.

In this application, proportions are given as percent by volume. If themixtures are applied from solution, this corresponds to percent by mass.

The above-mentioned mixed layers preferably comprise one or morecompounds according to the present application.

In a further embodiment of the present invention, the compound is usedin an emitting layer as matrix material in combination with one or moreemitting compounds, preferably phosphorescent emitting compounds.

The proportion of the matrix material in the emitting layer in this caseis between 50.0% and 99.9% by volume, preferably between 80.0% and 99.5%by volume, and more preferably between 92.0% and 99.5% by volume forfluorescent emitting layers and between 85.0% and 97.0% by volume forphosphorescent emitting layers.

Correspondingly, the proportion of the emitting compound is between 0.1%and 50.0% by volume, preferably between 0.5% and 20.0% by volume, andmore preferably between 0.5% and 8.0% by volume for fluorescent emittinglayers and between 3.0% and 15.0% by volume for phosphorescent emittinglayers.

An emitting layer of an organic electroluminescent device may alsocomprise systems comprising a plurality of matrix materials (mixedmatrix systems) and/or a plurality of emitting compounds. In this casetoo, the emitting compounds are generally those compounds having thesmaller proportion in the system and the matrix materials are thosecompounds having the greater proportion in the system. In individualcases, however, the proportion of a single matrix material in the systemmay be less than the proportion of a single emitting compound.

It is preferable that the compound is used as a component of mixedmatrix systems. The mixed matrix systems preferably comprise two orthree different matrix materials, more preferably two different matrixmaterials. Preferably, in this case, one of the two materials is amaterial having hole-transporting properties and the other material is amaterial having electron-transporting properties. The compound ispreferably the matrix material having hole-transporting properties. Thedesired electron-transporting and hole-transporting properties of themixed matrix components may, however, also be combined mainly orentirely in a single mixed matrix component, in which case the furthermixed matrix component(s) fulfill(s) other functions. The two differentmatrix materials may be present in a ratio of 1:50 to 1:1, preferably1:20 to 1:1, more preferably 1:10 to 1:1 and most preferably 1:4 to 1:1.Preference is given to using mixed matrix systems in phosphorescentorganic electroluminescent devices.

The mixed matrix systems may comprise one or more emitting compounds,preferably one or more phosphorescent emitting compounds. In general,mixed matrix systems are preferably used in phosphorescent organicelectroluminescent devices.

Particularly suitable matrix materials which can be used in combinationwith the compounds according to the present application as matrixcomponents of a mixed matrix system are selected from the preferredmatrix materials specified below for phosphorescent emitting compoundsor the preferred matrix materials for fluorescent emitting compounds,according to what type of emitting compound is used in the mixed matrixsystem.

Preferred phosphorescent emitting compounds for use in mixed matrixsystems are the same as detailed further up as generally preferredphosphorescent emitter materials.

Preferred embodiments of the different functional materials in theelectronic device are listed hereinafter.

Preferred phosphorescent emitting compounds are the following ones:

Preferred fluorescent emitting compounds are selected from the class ofthe arylamines. An arylamine or an aromatic amine in the context of thisinvention is understood to mean a compound containing three substitutedor unsubstituted aromatic or heteroaromatic ring systems bonded directlyto the nitrogen. Preferably, at least one of these aromatic orheteroaromatic ring systems is a fused ring system, more preferablyhaving at least 14 aromatic ring atoms. Preferred examples of these arearomatic anthracenamines, aromatic anthracenediamines, aromaticpyrenamines, aromatic pyrenediamines, aromatic chrysenamines or aromaticchrysenediamines. An aromatic anthracenamine is understood to mean acompound in which a diarylamino group is bonded directly to ananthracene group, preferably in the 9 position. An aromaticanthracenediamine is understood to mean a compound in which twodiarylamino groups are bonded directly to an anthracene group,preferably in the 9,10 positions. Aromatic pyrenamines, pyrenediamines,chrysenamines and chrysenediamines are defined analogously, where thediarylamino groups are bonded to the pyrene preferably in the 1-positionor 1,6-positions. Further preferred emitting compounds areindenofluorenamines and -fluorenediamines, benzoindenofluorenamines and-fluorenediamines, dibenzoindenofluoreneamines and -diamines, andindenofluorene derivatives having fused aryl groups. Likewise preferredare pyrenearylamines. Likewise preferred are benzoindenofluorenamines,benzofluorenamines, extended benzoindenofluorenes, phenoxazines, andfluorene derivatives bonded to furan units or to thiophene units.

Useful matrix materials, preferably for fluorescent emitting compounds,include materials of various substance classes. Preferred matrixmaterials are selected from the classes of the oligoarylenes (e.g.2,2′,7,7′-tetraphenylspirobifluorene or dinaphthylanthracene),especially of oligoarylenes containing fused aromatic groups,oligoarylenevinylenes (e.g. DPVBi or spiro-DPVBi), polypodal metalcomplexes, hole-conducting compounds, electron-conducting compounds,especially ketones, phosphine oxides, and sulphoxides, and atropisomers,boronic acid derivatives or benzanthracenes. Particularly preferredmatrix materials are selected from the classes of the oligoarylenescomprising naphthalene, anthracene, benzanthracene and/or pyrene oratropisomers of these compounds, the oligoarylenevinylenes, the ketones,the phosphine oxides and the sulphoxides. Very particularly preferredmatrix materials are selected from the classes of the oligoarylenescomprising anthracene, benzanthracene, benzophenanthrene and/or pyreneor atropisomers of these compounds. An oligoarylene in the context ofthis invention shall be understood to mean a compound in which at leastthree aryl or arylene groups are bonded to one another.

Preferred matrix materials for phosphorescent emitting compounds are, aswell as the compounds of the present application, aromatic ketones,aromatic phosphine oxides or aromatic sulphoxides or sulphones,triarylamines, carbazole derivatives, e.g. CBP(N,N-biscarbazolylbiphenyl) or carbazole derivatives, indolocarbazolederivatives, indenocarbazole derivatives, azacarbazole derivatives,bipolar matrix materials, silanes, azaboroles or boronic esters,triazine derivatives, zinc complexes, diazasilole or tetraazasilolederivatives, diazaphosphole derivatives, bridged carbazole derivatives,triphenylene derivatives, or lactams.

Suitable charge transport materials as usable in the hole injection orhole transport layer or electron blocking layer or in the electrontransport layer of the electronic device of the invention are, otherthan the compounds of the present application, for example, thecompounds disclosed in Y. Shirota et al., Chem. Rev. 2007, 107(4),953-1010, or other materials as used in these layers according to theprior art.

Particularly preferable materials for use in a hole transporting layerin the OLED are shown below:

Preferably, the inventive OLED comprises two or more differenthole-transporting layers. The compound according to the presentapplication may be used here in one or more of or in all thehole-transporting layers. In a preferred embodiment, the compound isused in exactly one or exactly two hole-transporting layers, and othercompounds, preferably aromatic amine compounds, are used in the furtherhole-transporting layers present. Further compounds which are usedalongside the compounds according to the present application, preferablyin hole-transporting layers of the OLEDs of the invention, areespecially indenofluorenamine derivatives, hexaazatriphenylenederivatives, amine derivatives with fused aromatics,monobenzoindenofluorenamines, dibenzoindenofluorenamines,spirobifluorenamines, fluorenamines, spirodibenzopyranamines,dihydroacridine derivatives, spirodibenzofurans andspirodibenzothiophenes, phenanthrenediarylamines,spirotribenzotropolones, spirobifluorenes with meta-phenyldiaminegroups, spirobisacridines, xanthenediarylamines, and9,10-dihydroanthracene spiro compounds with diarylamino groups.

Very particular preference is given to the use of spirobifluorenessubstituted by diarylamino groups in the 4 position as hole-transportingcompounds, and to the use of spirobifluorenes substituted by diarylaminogroups in the 2 position as hole-transporting compounds.

Materials used for the electron transport layer may be any materials asused according to the prior art as electron transport materials in theelectron transport layer. Especially suitable are aluminum complexes,for example Alq₃, zirconium complexes, for example Zrq₄, lithiumcomplexes, for example Liq, benzimidazole derivatives, triazinederivatives, pyrimidine derivatives, pyridine derivatives, pyrazinederivatives, quinoxaline derivatives, quinoline derivatives, oxadiazolederivatives, aromatic ketones, lactams, boranes, diazaphospholederivatives and phosphine oxide derivatives.

Particularly preferably electron transporting material for use in theOLEDs are shown below:

Preferred cathodes of the electronic device are metals having a low workfunction, metal alloys or multilayer structures composed of variousmetals, for example alkaline earth metals, alkali metals, main groupmetals or lanthanoids (e.g. Ca, Ba, Mg, Al, In, Mg, Yb, Sm, etc.).Additionally suitable are alloys composed of an alkali metal or alkalineearth metal and silver, for example an alloy composed of magnesium andsilver. In the case of multilayer structures, in addition to the metalsmentioned, it is also possible to use further metals having a relativelyhigh work function, for example Ag or Al, in which case combinations ofthe metals such as Ca/Ag, Mg/Ag or Ba/Ag, for example, are generallyused. It may also be preferable to introduce a thin interlayer of amaterial having a high dielectric constant between a metallic cathodeand the organic semiconductor. Examples of useful materials for thispurpose are alkali metal or alkaline earth metal fluorides, but also thecorresponding oxides or carbonates (e.g. LiF, Li₂O, BaF₂, MgO, NaF, CsF,Cs₂CO₃, etc.). It is also possible to use lithium quinolinate (LiQ) forthis purpose. The layer thickness of this layer is preferably between0.5 and 5 nm.

Preferred anodes are materials having a high work function. Preferably,the anode has a work function of greater than 4.5 eV versus vacuum.Firstly, metals having a high redox potential are suitable for thispurpose, for example Ag, Pt or Au. Secondly, metal/metal oxideelectrodes (e.g. Al/Ni/NiO_(x), Al/PtO_(x)) may also be preferred. Forsome applications, at least one of the electrodes has to be transparentor partly transparent in order to enable the irradiation of the organicmaterial (organic solar cell) or the emission of light (OLED, O-laser).Preferred anode materials here are conductive mixed metal oxides.Particular preference is given to indium tin oxide (ITO) or indium zincoxide (IZO). Preference is further given to conductive doped organicmaterials, especially conductive doped polymers. In addition, the anodemay also consist of two or more layers, for example of an inner layer ofITO and an outer layer of a metal oxide, preferably tungsten oxide,molybdenum oxide or vanadium oxide.

The device is structured appropriately (according to the application),contact-connected and finally sealed, in order to rule out damagingeffects by water and air.

In a preferred embodiment, the electronic device is characterized inthat one or more layers are coated by a sublimation process. In thiscase, the materials are applied by vapour deposition in vacuumsublimation systems at an initial pressure of less than 10⁻⁵ mbar,preferably less than 10⁻⁶ mbar. In this case, however, it is alsopossible that the initial pressure is even lower, for example less than10⁻⁷ mbar.

Preference is likewise given to an electronic device, characterized inthat one or more layers are coated by the OVPD (organic vapour phasedeposition) method or with the aid of a carrier gas sublimation. In thiscase, the materials are applied at a pressure between 10⁻⁵ mbar and 1bar. A special case of this method is the OVJP (organic vapour jetprinting) method, in which the materials are applied directly by anozzle and thus structured (for example M. S. Arnold et al., Appl. Phys.Lett. 2008, 92, 053301).

Preference is additionally given to an electronic device, characterizedin that one or more layers are produced from solution, for example byspin-coating, or by any printing method, for example screen printing,flexographic printing, nozzle printing or offset printing, but morepreferably LITI (light-induced thermal imaging, thermal transferprinting) or inkjet printing. For this purpose, soluble compounds areneeded. High solubility can be achieved by suitable substitution of thecompounds.

It is further preferable that an electronic device of the invention isproduced by applying one or more layers from solution and one or morelayers by a sublimation method.

According to the invention, the electronic devices comprising one ormore compounds according to the present application can be used indisplays, as light sources in lighting applications and as light sourcesin medical and/or cosmetic applications.

EXAMPLES A) Synthesis Examples

The following syntheses are carried out under a protective-gasatmosphere, unless indicated otherwise. The starting materials arecommercially available. The numbers in square brackets in the case ofthe starting materials known from the literature are the correspondingCAS numbers.

Synthesis of6-[4-(2-chloro-9-phenyl-9H-fluoren-9-yl)phenyl]-8-oxatricyclo[7.4.0.0^(2,7)]trideca-1(13),2,4,6,9,11-hexaene2a

Synthesis of6-(4-benzoylphenyl)-8-oxatricyclo[7.4.0.0^(2,7)]trideca-1(13),2,4,6,9,11-hexaene1a

50 g (191.5 mmol) of (4-bromo-phenyl)-phenyl-methanone and 50.7 g (239.4mmol) of dibenzofuran-4-yl-boronic acid, 26.5 g (23 mmol, 0.12 eq.) ofPd(P(Ph₃))₄, and 680 mL 2M solution (1365 mmol, 7 eq.) of Na₂CO₃ aredissolved in 1300 mL of ethylenglycoldiethylether. The reaction mixtureis stirred under reflux and agitated under an argon atmosphere for 12hours. After cooling to room temperature, the mixture is extracted withethyl acetate. The organic phase is dried with Na₂SO₄ and the filtrateis evaporated in vacuo, and the residue is purified by chromatography(mixture heptane/AcOEt). The product is isolated in the form of anoff-white solid (46 g, 68% of theory).

The synthesis of further derivatives is carried out analogously:

Ex. Boronic acid Bromide Product Yield 1b

76% 1c

74% 1d

80% 1f

70% 1g

86% 1h

71% 1i

77% 1j

65% 1k

81% 1l

70% 1ll

71% 1m

76% 1n

81% 1o

68%

1p

80%

Synthesis of Synthesis of6-[4-(2-chloro-9-phenyl-9H-fluoren-9-yl)phenyl]-8-oxatricyclo[7.4.0.0^(2,7)]trideca-1(13),2,4,6,9,11-hexaene2a

A solution of 2-bromo-4′-chloro-biphenyl (43 g, 158 mmol) in THF (465ml) is treated with 58 mL of n-BuLi (2.2 M in hexane, 144 mmol) underargon at −78° C. The mixture is stirred for 30 minutes. A solution of 1a(50 g, 144 mmol) in 230 mL THF is added dropwise. The reaction proceedsat −78° C. for 30 minutes and then is stirred at room temperatureovernight. The reaction is quenched with water and the solid isfiltered. Without further purification, a solution of the alcohol in 700mL toluene and 2.9 g p-toluenesulfonic acid is refluxed overnight. Aftercooling, the organic phase is washed with water and the solvent isremoved under vacuum. The product is isolated in the form of a whitesolid (55 g, 74% of theory).

The following compounds are synthesized analogously:

Ex. Ketone Halogen Product Yield 2b

81% 2c

72% 2d

33% 2e

82% 2f

80% 2g

75% 2h

75% 2i

64% 2j

60% 2k

70% 2l

80% 2m

75% 2n

80% 2o

77% 2p

82% 2q

84% 2r

78% 2s

74% 2t

70%

Synthesis ofN-{[1,1′-biphenyl]-4-yl}-N-(9,9-dimethyl-9H-fluoren-2-yl)-9-(4-{8-oxatricyclo[7.4.0.0^(2,7)]tridecal(9),2,4,6,10,12-hexaen-6-yl}phenyl)-9-phenyl-9H-fluoren-2-amine 4a

S-Phos (0.645 g, 1.6 mmol), Pd₂(dba)₃ (0.72 g, 0.8 mmol) and sodiumtert-butoxide (5 g, 52.4 mmol) are added to a solution ofbiphenyl-4-yl-(9,9-dimethyl-9H-fluoren-2-yl)-amine (9.5 g, 26.2 mmol)and fluorene 3a (9.5 g, 26.2 mmol) in degassed toluene (140 ml), and themixture is heated under reflux for 10 h. The reaction mixture is cooledto room temperature, extended with toluene and filtered through Celite.The filtrate is evaporated in vacuo, and the residue is crystallisedfrom toluene/heptane. The crude product is extracted in a Soxhletextractor (toluene) and purified by zone sublimation in vacuo twice. Theproduct is isolated in the form of an off-white solid (11 g, 40% oftheory).

The following compounds are obtained analogously:

Halogenated Ex. Fluorene Amine Product Yield 4b

53% 4c

65% 4d

51% 4e

62% 4f

58% 4g

63% 4h

55% 4i

77% 4j

76% 4k

65% 4l

52% 4m

73% 4n

59% 4o

55% 4p

55% 4q

75% 4r

70% 4s

72% 4t

62% 4u

45% 4v

66% 4w

66% 4x

71% 4y

49% 4z

65% 4aa

73% 4ab

70% 4ac

80% 4ad

75% 4ae

50% 4af

40% 4ag

76% 4ah

54% 4ai

47% 4aj

40% 4ak

37% 4al

42% 4am

51% 4an

47%

Synthesis of N-{[1,1′-biphenyl]-4-yl}-9,9-dimethyl-N-{4-[9-(4-{8-oxatricyclo[7.4.0.0^(2,7)]tridecal(13),2(7),3,5,9,11-hexaen-6-yl}phenyl)-9-phenyl-9H-fluoren-2-yl]phenyl}-9H-fluoren-2-amine5a

59.1 g (101.8 mmol) of Biphenyl-4-yl-(9,9-dimethyl-9H-fluoren-2-yl(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-phenyl]-amine, 52.8 g(101.8 mmol) fluorene 3a, 3.88 g (5.14 mmol) of PdCl₂(Cy)₃, 31.2 g(205.6 mmol) of cesium fluoride are dissolved in 800 mL of toluene. Thereaction mixture is refluxed and agitated under an argon atmosphere for12 hours and after cooling to room temperature, the mixture is filteredthrough Celite. The filtrate is evaporated in vacuo, and the residue iscrystallised from heptane. The crude product is extracted in a Soxhletextractor (toluene) and purified by zone sublimation in vacuo twice. Theproduct is isolated in the form of a white solid (46 g, 50% of theory).

The following compounds are synthesized analogously:

Halogenated Ex. fluorene Amine Product Yield 5b

53% 5c

65% 5d

50% 5e

53% 5f

60% 5g

55% 5h

65% 5i

54% 5j

65% 5k

45% 5l

80% 5m

67% 5n

60% 5o

50% 5p

62% 5q

55% 5r

66% 5s

52% 5t

47% 5u

53%

B) Device Examples B-1) General Preparation and Characterization Methods

OLEDs comprising compounds according to the present application areprepared by the following general process: The substrates used are glassplates coated with structured ITO (indium tin oxide) in a thickness of50 nm. The OLEDs have the following layer structure:substrate/hole-injection layer (HIL)/hole-transport layer(HTL)/electron-blocking layer (EBL)/emission layer(EML)/electron-transport layer (ETL)/electron-injection layer (EIL) andfinally a cathode. The cathode is formed by an aluminium layer with athickness of 100 nm. The specific device setup of the OLEDs is shown inTables 1a to 1c, and the materials for the various layers of the OLEDsare shown in Table 3.

All materials are applied by thermal vapour deposition in a vacuumchamber. The emission layer here always consists of at least one matrixmaterial (host material) and an emitting dopant (emitter), which isadmixed with the matrix material or matrix materials in a certainproportion by volume by coevaporation. An expression such as H:SEB (5%)here means that material H is present in the layer in a proportion byvolume of 95% and SEB is present in the layer in a proportion by volumeof 5%. Analogously, other layers may also consist of a mixture of two ormore materials.

The OLEDs are characterised by standard methods. For this purpose, theelectroluminescence spectra and the external quantum efficiency (EQE,measured in percent) as a function of the luminous density, calculatedfrom current/voltage/luminous density characteristic lines (IULcharacteristic lines) assuming Lambert emission characteristics, and thelifetime are determined. The expression EQE @ 10 mA/cm² denotes theexternal quantum efficiency at an operating current density of 10mA/cm². LT80 @ 60 mA/cm² is the lifetime until at a current density of60 mA/cm², the OLED has dropped from its initial luminance of e.g. 5000cd/m² to 80% of the initial intensity, i.e. to 4000 cd/m² without usingany acceleration factor.

B-2) Use of the Compounds in the EBL of Blue Fluorescent OLEDs

The compounds HTM-1 to HTM-3 according to the present application areused in the EBL of a blue fluorescent OLED stack, as shown below inTable 1a.

TABLE 1a Device Setup HTL EBL ETL EIL HIL Thickness/ Thickness/ EMLThickness/ Thickness/ Ex. Thickness/nm nm nm Thickness/nm nm nm E1 HTM:p-dopant (5%) HTM HTM-1 H: SEB(5%) ETM: LiQ(50%) LiQ 20 nm 180 nm 10 nm20 nm 30 nm 1 nm E2 HTM: p-dopant (5%) HTM HTM-2 H: SEB(5%) ETM:LiQ(50%) LiQ 20 nm 180 nm 10 nm 20 nm 30 nm 1 nm E3 HTM: p-dopant (5%)HTM HTM-3 H: SEB(5%) ETM: LiQ(50%) LiQ 20 nm 180 nm 10 nm 20 nm 30 nm 1nm

In such device setup, very good results for EQE, lifetime and voltageare obtained with the compounds, as shown in the table below.

TABLE 2a Data for the OLEDs U @ 10 EQE @ 10 LT80 @ 60 Ex. mA/cm² (V)mA/cm² (%) mA/cm² ( h) E1 4.1 9.1 230 E2 3.8 8.2 230 E3 3.9 8.5 270

B-3) Use of the Compounds in the EBL of Green Phosphorescent OLEDs

The compounds HTM-1 to HTM-4 according to the present application areused in the EBL of a blue fluorescent OLED stack, as shown below inTable 1b.

TABLE 1b Device Setup HTL EBL ETL EIL HIL Thickness/ Thickness/ EMLThickness/ Thickness/ Ex. Thickness/nm nm nm Thickness/nm nm nm E4 HTM:p-dopant (5%) HTM HTM-1 TMM-1: TMM-2 ETM: LiQ(50%) LiQ 20 nm 220 nm 10nm (28%):TEG(12%) 30 nm 1 nm 30 nm E5 HTM: p-dopant (5%) HTM HTM-2TMM-1: TMM-2 ETM: LiQ(50%) LiQ 20 nm 220 nm 10 nm (28%):TEG(12%) 30 nm 1nm 30 nm E6 HTM: p-dopant (5%) HTM HTM-3 TMM-1: TMM-2 ETM: LiQ(50%) LiQ20 nm 220 nm 10 nm (28%):TEG(12%) 30 nm 1 nm 30 nm E7 HTM: p-dopant (5%)HTM HTM-4 TMM-1: TMM-2 ETM: LiQ(50%) LiQ 20 nm 220 nm 10 nm(28%):TEG(12%) 30 nm 1 nm 30 nm

In such device setup, very good results for EQE, lifetime and voltageare obtained with the compounds, as shown in the table below.

TABLE 2b Data for the OLEDs U @ 10 EQE @ 10 LT80 @40 Ex. mA/cm² (V)mA/cm² (%) mA/cm² (h) E4 4.2 18.0 300 E5 3.8 16.1 350 E6 3.9 16.8 320 E74.3 16.7 280

B-4) Use of the Compounds in the HTL of Blue Fluorescent OLEDs

The compounds HTM-2 and HTM-3 according to the present application areused in the HTL of a blue fluorescent OLED stack, as shown below inTable 1c.

TABLE 1c Device Setup HTL EBL ETL EIL HIL Thickness/ Thickness/ EMLThickness/ Thickness/ Ex. Thickness/nm nm nm Thickness/nm nm nm E8HTM-2: p-dopant (5%) HTM-2 EBM H: SEB(5%) ETM: LiQ(50%) LiQ 20 nm 180 nm10 nm 20 nm 30 nm 1 nm E9 HTM-3: p-dopant (5%) HTM-3 EBM H: SEB(5%) ETM:LiQ(50%) LiQ 20 nm 180 nm 10 nm 20 nm 30 nm 1 nm

In such device setup, very good results for EQE, lifetime and voltageare obtained with the compounds, as shown in the table below.

TABLE 2c Data for the OLEDs U @ 10 EQE @ 10 LT80 @ 60 Ex. mA/cm² (V)mA/cm² (%) mA/cm² (h) E8 4.3 8.9 220 E9 4.2 8.2 300

TABLE 3 Materials for the OLEDs

p-dopant

HTM

EBM

H

SEB

TMM-1

TMM-2

TEG

ETM

LiQ

HTM-1

HTM-2

HTM-3

HTM-4

1.-20. (canceled)
 21. A compound of formula (I)

where the following applies to the variable groups: Z is C, if a group—[Ar²]_(n)-A is bonded to it; and Z is selected, identically ordifferently at each occurrence, from CR¹ and N, if no group —[Ar²]_(n)-Ais bonded to it; Y is C, if a group Ar¹ is bonded to it; and Y isselected, identically or differently on each occurrence, from CR³ and N,if no group Ar¹ is bonded to it; X is O or S; Ar¹ is, identically ordifferently at each occurrence, selected from aromatic ring systemshaving 6 to 40 aromatic ring atoms, which are substituted by radicalsR⁴, and heteroaromatic ring systems having 5 to 40 aromatic ring atoms,which are substituted by radicals R⁴; Ar² is, identically or differentlyat each occurrence, selected from aromatic ring systems having 6 to 40aromatic ring atoms, which are substituted by radicals R⁵, andheteroaromatic ring systems having 5 to 40 aromatic ring atoms, whichare substituted by radicals R⁵; A corresponds to the following formula

 which is bonded via the dotted line; Ar³ and Ar⁴ are, identically ordifferently at each occurrence, selected from aromatic ring systemshaving 6 to 40 aromatic ring atoms, which are substituted by radicalsR⁵, and heteroaromatic ring systems having 5 to 40 aromatic ring atoms,which are substituted by radicals R⁵; T is a single bond or a divalentgroup selected from C(R⁵)₂, Si(R⁵)₂, N(R⁵), O, and S; k is 0 or 1, wherek=0 means that T does not occur and the groups Ar³ and Ar⁴ are notconnected; R¹ is selected, identically or differently at eachoccurrence, from H, D, F, Cl, Br, I, C(═O)R⁶, CN, Si(R⁶)₃, N(R⁶)₂,P(═O)(R⁶)₂, OR⁶, S(═O)R⁶, S(═O)₂R⁶, straight-chain alkyl or alkoxygroups having 1 to 20 C atoms, branched or cyclic alkyl or alkoxy groupshaving 3 to 20 C atoms, alkenyl or alkynyl groups having 2 to 20 Catoms, aromatic ring systems having 6 to 40 aromatic ring atoms, andheteroaromatic ring systems having 5 to 40 aromatic ring atoms; wheretwo or more radicals R¹ may be connected to each other to form a ring;where the said alkyl, alkoxy, alkenyl and alkynyl groups and the saidaromatic and heteroaromatic ring systems are in each case substituted byradicals R⁶, and where one or more CH₂ groups in the said alkyl, alkoxy,alkenyl and alkynyl groups may in each case be replaced by —R⁶C═CR⁶—,—C≡C—, Si(R⁶)₂, C═O, C═NR⁶, —C(═O)O—, —C(═O)NR⁶—, NR⁶, P(═O)(R⁶), —O—,—S—, SO or SO₂; R² is selected, identically or differently at eachoccurrence, from H, D, F, Cl, Br, I, CN, Si(R⁶)₃, N(R⁶)₂, straight-chainalkyl or alkoxy groups having 1 to 20 C atoms, branched or cyclic alkylor alkoxy groups having 3 to 20 C atoms, alkenyl or alkynyl groupshaving 2 to 20 C atoms, aromatic ring systems having 6 to 40 aromaticring atoms, and heteroaromatic ring systems having 5 to 40 aromatic ringatoms; where the said alkyl, alkoxy, alkenyl and alkynyl groups and thesaid aromatic and heteroaromatic ring systems are in each casesubstituted by radicals R⁶, and where one or more CH₂ groups in the saidalkyl, alkoxy, alkenyl and alkynyl groups may in each case be replacedby —R⁶C═CR⁶—, —C≡C—, Si(R⁶)₂, C═O, C═NR⁶, —C(═O)O—, —C(═O)NR⁶—, NR⁶,P(═O)(R⁶), —O—, —S—, SO or SO₂; R³ is selected, identically ordifferently at each occurrence, from H, D, F, Cl, Br, I, C(═O)R⁶, CN,Si(R⁶)₃, N(R⁶)₂, P(═O)(R⁶)₂, OR⁶, S(═O)R⁶, S(═O)₂R⁶, straight-chainalkyl or alkoxy groups having 1 to 20 C atoms, branched or cyclic alkylor alkoxy groups having 3 to 20 C atoms, alkenyl or alkynyl groupshaving 2 to 20 C atoms, aromatic ring systems having 6 to 40 aromaticring atoms, and heteroaromatic ring systems having 5 to 40 aromatic ringatoms; where two or more radicals R³ may be connected to each other toform a ring; where the said alkyl, alkoxy, alkenyl and alkynyl groupsand the said aromatic and heteroaromatic ring systems are in each casesubstituted by radicals R⁶, and where one or more CH₂ groups in the saidalkyl, alkoxy, alkenyl and alkynyl groups may in each case be replacedby —R⁶C═CR⁶—, —C≡C—, Si(R⁶)₂, C═O, C═NR⁶, —C(═O)O—, —C(═O)NR⁶—, NR⁶,P(═O)(R⁶), —O—, —S—, SO or SO₂; R⁴ is selected, identically ordifferently at each occurrence, from H, D, F, Cl, Br, I, C(═O)R⁶, CN,Si(R⁶)₃, N(R⁶)₂, P(═O)(R⁶)₂, OR⁶, S(═O)R⁶, S(═O)₂R⁶, straight-chainalkyl or alkoxy groups having 1 to 20 C atoms, branched or cyclic alkylor alkoxy groups having 3 to 20 C atoms, alkenyl or alkynyl groupshaving 2 to 20 C atoms, aromatic ring systems having 6 to 40 aromaticring atoms, and heteroaromatic ring systems having 5 to 40 aromatic ringatoms; where two or more radicals R⁴ may be connected to each other toform a ring; where the said alkyl, alkoxy, alkenyl and alkynyl groupsand the said aromatic and heteroaromatic ring systems are in each casesubstituted by radicals R⁶, and where one or more CH₂ groups in the saidalkyl, alkoxy, alkenyl and alkynyl groups may in each case be replacedby —R⁶C═CR⁶—, —C≡C—, Si(R⁶)₂, C═O, C═NR⁶, —C(═O)O—, —C(═O)NR⁶—, NR⁶,P(═O)(R⁶), —O—, —S—, SO or SO₂; R⁵ is selected, identically ordifferently at each occurrence, from H, D, F, Cl, Br, I, C(═O)R⁶, CN,Si(R⁶)₃, N(R⁶)₂, P(═O)(R⁶)₂, OR⁶, S(═O)R⁶, S(═O)₂R⁶, straight-chainalkyl or alkoxy groups having 1 to 20 C atoms, branched or cyclic alkylor alkoxy groups having 3 to 20 C atoms, alkenyl or alkynyl groupshaving 2 to 20 C atoms, aromatic ring systems having 6 to 40 aromaticring atoms, and heteroaromatic ring systems having 5 to 40 aromatic ringatoms; where two or more radicals R⁵ may be connected to each other toform a ring; where the said alkyl, alkoxy, alkenyl and alkynyl groupsand the said aromatic and heteroaromatic ring systems are in each casesubstituted by radicals R⁶, and where one or more CH₂ groups in the saidalkyl, alkoxy, alkenyl and alkynyl groups may in each case be replacedby —R⁶C═CR⁶—, —C≡C—, Si(R⁶)₂, C═O, C═NR⁶, —C(═O)O—, —C(═O)NR⁶—, NR⁶,P(═O)(R⁶), —O—, —S—, SO or SO₂; R⁶ is selected, identically ordifferently at each occurrence, from H, D, F, Cl, Br, I, C(═O)R⁷, CN,Si(R⁷)₃, N(R⁷)₂, P(═O)(R⁷)₂, OR⁷, S(═O)R⁷, S(═O)₂R⁷, straight-chainalkyl or alkoxy groups having 1 to 20 C atoms, branched or cyclic alkylor alkoxy groups having 3 to 20 C atoms, alkenyl or alkynyl groupshaving 2 to 20 C atoms, aromatic ring systems having 6 to 40 aromaticring atoms, and heteroaromatic ring systems having 5 to 40 aromatic ringatoms; where two or more radicals R⁶ may be connected to each other toform a ring; where the said alkyl, alkoxy, alkenyl and alkynyl groupsand the said aromatic and heteroaromatic ring systems are in each casebe substituted by radicals R⁷, and where one or more CH₂ groups in thesaid alkyl, alkoxy, alkenyl and alkynyl groups may in each case bereplaced by —R⁷C═CR⁷—, —C≡C—, Si(R⁷)₂, C═O, C═NR⁷, —C(═O)O—, —C(═O)NR⁷—,NR⁷, P(═O)(R⁷), —O—, —S—, SO or SO₂; R⁷ is selected, identically ordifferently at each occurrence, from H, D, F, Cl, Br, I, CN, alkylgroups having 1 to 20 C atoms, aromatic ring systems having 6 to 40 Catoms, or heteroaromatic ring systems having 5 to 40 aromatic ringatoms; where the said alkyl groups, aromatic ring systems andheteroaromatic ring systems may be substituted by one or more radicalsselected from F and CN; m is 1, 2, 3, or 4; n is 0, 1, 2, 3, or
 4. 22.The compound according to claim 21, wherein it is a monoamine.
 23. Thecompound according to claim 21, wherein the group —[Ar²]_(n)-A is bondedin position 2 or 4, on the fluorene sub-structure of formula (I). 24.The compound according to claim 21, wherein X is O.
 25. The compoundaccording to claim 21, wherein m is 1 or
 2. 26. The compound accordingto claim 21, wherein groups —[Ar¹]_(m)— for the case of m=1 are selectedfrom 1,2-phenylene, 1,3-phenylene and 1,4-phenylene, where the phenylenegroups are substituted with radicals R⁴.
 27. The compound according toclaim 21, wherein n is 0, so that the group Ar² is not present, and thefluorene moiety and the amine nitrogen in formula (I) are directlyconnected to each other.
 28. The compound according to claim 21, whereinn is
 1. 29. The compound according to claim 28, wherein group—[Ar²]_(n)— is selected from divalent groups derived from phenyl,biphenyl, terphenyl, naphthalene, fluorene, indenofluorene,indenocarbazole, spirobifluorene, dibenzofuran, dibenzothiophene, andcarbazole, which are substituted with radicals R⁵.
 30. The compoundaccording to claim 21, wherein k=0, i.e. groups Ar³ and Ar⁴ in group Aare not linked to each other by a group T.
 31. The compound according toclaim 21, wherein Ar³ and Ar⁴ are selected, identically or differently,from phenyl, biphenyl, terphenyl, quaterphenyl, naphthyl, fluorenyl,9,9′-dimethylfluorenyl and 9,9′-diphenylfluorenyl, benzofluorenyl,spirobifluorenyl, indenofluorenyl, indenocarbazolyl, dibenzofuranyl,dibenzothiophenyl, carbazolyl, benzofuranyl, benzothiophenyl,benzo-condensed dibenzofuranyl, benzo-condensed dibenzothiophenyl,phenyl substituted with naphthyl, phenyl substituted with fluorenyl,phenyl substituted with spirobifluorenyl, phenyl substituted withdibenzofuranyl, phenyl substituted with dibenzothiophene, phenylsubstituted with carbazolyl, phenyl substituted with pyridyl, phenylsubstituted with pyrimidyl, and phenyl substituted with triazinyl, wherethe groups are each substituted with radicals R⁵.
 32. The compoundaccording to claim 21, wherein R¹ is selected, identically ordifferently, from H, D, F, CN, Si(R⁶)₃, N(R⁶)₂, straight-chain alkyl oralkoxy groups having 1 to 20 C atoms, branched or cyclic alkyl or alkoxygroups having 3 to 20 C atoms, aromatic ring systems having 6 to 40aromatic ring atoms, and heteroaromatic ring systems having 5 to 40aromatic ring atoms; where the said alkyl and alkoxy groups and the saidaromatic and heteroaromatic ring systems are substituted by radicals R⁶,and where one or more CH₂ groups in the said alkyl and alkoxy groups mayin each case be replaced by —C≡C—, —R⁶C═CR⁶—, Si(R⁶)₂, C═O, C═NR⁶,—NR⁶—, —O—, —S—, —C(═O)O— or —C(═O)NR⁶—; and R² is F, Si(R⁶)₃, astraight-chain alkyl group having 1 to 20 C atoms, a branched or cyclicalkyl group having 3 to 20 C atoms, an aromatic ring system having 6 to40 aromatic ring atoms, or a heteroaromatic ring system having 5 to 40aromatic ring atoms; where the said alkyl group and the said aromatic orheteroaromatic ring system are substituted by radicals R⁶; and R³ isselected, identically or differently, from H, D, F, CN, Si(R⁶)₃, N(R⁶)₂,straight-chain alkyl or alkoxy groups having 1 to 20 C atoms, branchedor cyclic alkyl or alkoxy groups having 3 to 20 C atoms, aromatic ringsystems having 6 to 40 aromatic ring atoms, and heteroaromatic ringsystems having 5 to 40 aromatic ring atoms; where the said alkyl andalkoxy groups and the said aromatic and heteroaromatic ring systems aresubstituted by radicals R⁶, and where one or more CH₂ groups in the saidalkyl and alkoxy groups may in each case be replaced by —C≡C—,—R⁶C═CR⁶—, Si(R⁶)₂, C═O, C═NR⁶, —NR⁶—, —O—, —S—, —C(═O)O— or —C(═O)NR⁶—;and R⁴ is selected, identically or differently, from H, D, F, CN,Si(R⁶)₃, N(R⁶)₂, straight-chain alkyl or alkoxy groups having 1 to 20 Catoms, branched or cyclic alkyl or alkoxy groups having 3 to 20 C atoms,aromatic ring systems having 6 to 40 aromatic ring atoms, andheteroaromatic ring systems having 5 to 40 aromatic ring atoms; wherethe said alkyl and alkoxy groups and the said aromatic andheteroaromatic ring systems are substituted by radicals R⁶, and whereone or more CH₂ groups in the said alkyl and alkoxy groups may in eachcase be replaced by —C≡C—, —R⁶C═CR⁶—, Si(R⁶)₂, C═O, C═NR⁶, —NR⁶—, —O—,—S—, —C(═O)O— or —C(═O)NR⁶—; and R⁵ is selected, identically ordifferently, from H, D, F, CN, Si(R⁶)₃, N(R⁶)₂, straight-chain alkyl oralkoxy groups having 1 to 20 C atoms, branched or cyclic alkyl or alkoxygroups having 3 to 20 C atoms, aromatic ring systems having 6 to 40aromatic ring atoms, and heteroaromatic ring systems having 5 to 40aromatic ring atoms; where the said alkyl and alkoxy groups and the saidaromatic and heteroaromatic ring systems are substituted by radicals R⁶,and where one or more CH₂ groups in the said alkyl and alkoxy groups mayin each case be replaced by —C≡C—, —R⁶C═CR⁶—, Si(R⁶)₂, C═O, C═NR⁶,—NR⁶—, —O—, —S—, —C(═O)O— or —C(═O)NR⁶—; and R⁶ is selected, identicallyor differently, from H, D, F, CN, Si(R⁷)₃, N(R⁷)₂, straight-chain alkylor alkoxy groups having 1 to 20 C atoms, branched or cyclic alkyl oralkoxy groups having 3 to 20 C atoms, aromatic ring systems having 6 to40 aromatic ring atoms, and heteroaromatic ring systems having 5 to 40aromatic ring atoms; where the said alkyl and alkoxy groups and the saidaromatic and heteroaromatic ring systems are substituted by radicals R⁷,and where one or more CH₂ groups in the said alkyl and alkoxy groups mayin each case be replaced by —C≡C—, —R⁷C═CR⁷—, Si(R⁷)₂, C═O, C═NR⁷,—NR⁷—, —O—, —S—, —C(═O)O— or —C(═O)NR⁷—.
 33. The compound according toclaim 21, wherein R² is selected from the following groups

where the dotted bond represents the bond to the rest of the formula.34. The compound according to claim 21, wherein the compound conforms toone of the following formulae

where X is selected, identically or differently, from O and S.
 35. Amethod for preparation of the compound of formula (I) according to claim21, wherein a biphenyl derivative which is substituted with two reactivegroups, of which at least one is present in the ortho-position to thephenyl-phenyl bond of the biphenyl derivative, is metalated.
 36. Anoligomer, polymer or dendrimer, comprising one or more compounds offormula (I) according to claim 21, where the bond(s) to the polymer,oligomer or dendrimer may be localised at any desired positions informula (I) substituted by R¹, R², R³, R⁴, or R⁵.
 37. A formulation,comprising at least one compound of formula (I) according to claim 21and at least one solvent.
 38. An electronic device, comprising at leastone compound according to claim
 21. 39. The electronic device accordingto claim 38, wherein the device is an organic electroluminescent device,comprising anode, cathode and at least one emitting layer, where atleast one organic layer of the device, which is a hole transport layer,an electron blocking layer or a hole injection layer, comprises the atleast one compound.
 40. A method comprising incorporating the compoundaccording to claim 21 in an electronic device.